Study of Nicotinamide in Early Onset Preeclampsia

Diagnosis and Inclusion Criteria * Maternal age 18-55 years * Singleton pregnancy with no known fetal anomalies * Early-onset preeclampsia OR early-onset severe gestational hypertension defined as: * Early-onset: between 24 weeks 0 days and -33 weeks 3 days, based on menstrual dating confirmed by first or second trimester ultrasound OR second trimester ultrasound if menstrual dating unavailable; * Preeclampsia: * New onset hypertension and proteinuria, with systolic BP \> 140 mm Hg and/or diastolic BP \> 90 mm Hg on two occasions 6 hours apart and \> 300 mg proteinuria on 24 hour urine collection OR urine P/C ratio \>0.3; * New onset hypertension and NO proteinuria, with systolic BP \> 140 mm Hg and/or diastolic BP \> 90 mm Hg on two occasions 6 hours apart and one or more of the following: serum creatinine \>1.1 mg/dL or doubling from baseline ,or central nervous system symptoms or visual changes * Severe preeclampsia defined as new onset systolic BP \> 160 mm Hg and/or diastolic BP \> 105 with proteinuria as above or or without proteinuria and one or more of the following criteria listed above * Candidate for expectant management for at least 48 hours * Deemed clinically stable by primary clinician and candidate for expectant management (delayed delivery) for at least 48 hours; * Maternal liver function tests \< 2x ULN * Maternal platelet count \> 100,000 mm³ * Planned expectant management * Pre-existing medical diseases such as hypertension, diabetes, endocrine disorders, gastrointestinal diseases, are well controlled * Fetal well-being established by estimated fetal weight \> 5th %tile; normal amniotic fluid volume (MVP \> 2 cm); normal Umbilical Artery (UA) Dopplers; or reactive Non Stress Test (NST) or Biophysical Profile (BPP) \> 6 * Delivery not anticipated within 48 hours of enrollment Exclusion Criteria * Pre-existing renal disease (creatinine \> 1.5 mg/dL) * Any pre-existing medical condition that would increase risk for liver toxicity (e.g. hepatitis B or C; HIV; Isoniazid (INH) use) * Eclampsia; cerebral edema on CT/MRI; headache unrelieved by analgesics * Evidence of liver dysfunction (LFTs \> 2x ULN) * Thrombocytopenia (platelets \< 100,000 mm³) * Pulmonary edema * HELLP syndrome * Evidence of fetal compromise: Estimated Fetal Weight (EFW) \< 5th percentile; or BPP \< 6; or absent or reverse diastolic UA blood flow; or oligohydramnios (MVP \< 2 cm) * Placental abruption defined as unexplained vaginal bleeding * Preterm labor defined as regular contractions and cervical change * Any condition deemed by the investigator to be a risk to mother or fetus in completion of the study * Any condition deemed by the investigator to require delivery within 48 hours